Digital evidence certification: standardised device identification, control declaration and hashed integrity attestation in a two part form. Two-part certification form requiring device/digital source identification, declaration of lawful control and ownership/operation status, and specification of HASH value(s) with the hashing algorithm used (examples: SHA1, SHA256, MD5 or other legally acceptable standard); hash report to be enclosed, with name, signature, date, time and place provided by the producing party and by an expert.